In performing a sanding operation, it is sometimes desirable to apply water to the surface being sanded in order to cool and lubricate that surface and carry away abraded particles. The water may be delivered to the work surface by a hose, spray, or the like, or may be introduced through the sanding tool itself. U.S. Pat. No. 5,022,190 issued Jun. 11, 1991 to Alma A. Hutchins shows a tool having a sanding head which is driven orbitally by a motor of the device, and by which a sheet of sandpaper is carried for engaging and acting on a work surface, with the head containing passages through which water is delivered to openings in the sandpaper for emission onto the work surface at the location of the sanding operation. In that patent, water is supplied to the tool through a hose connected to a pressurized source of the water. There have also been prior tools in which the exhaust air from a motor driving the tool has been utilized to induce a flow of water to the work surface by aspirator action. However, in these tools, the exhaust air intermixes with the water and is discharged onto the work surface with the water, and may contaminate the work surface if the air in flowing through the motor has picked up any dirt, lubricant, or other unwanted substances.